Modern presentation computer programs ("presentation programs") allow human users to use a general-purpose computer and an attached display device to design and present a slide show-type visual presentation ("presentation") comprised of a sequence of visual ("images"), or "slides." Typically, such presentation programs have a presentation editing mode in which users may design and revise presentations and a presentation mode in which users may present presentations. Presentation programs are useful because they enable a user who is not a graphic design artist to design a consistent, professional-looking visual presentation that can accompany and enhance a verbal presentation.
A user designs a presentation by interacting with the presentation program to prepare a set of images to be presented during the presentation. It is typical for the user to designate a particular linear sequence for the images to presented in during the presentation. This can be characterized as creating a "link" from each image to the image that follows it in the sequence designated by the user. When the presentation is initiated, the images are presented in the designated sequence. From a particular current image being displayed, the presentation program presents the next image in the designated sequence, following the link from the current image, either (a) after a designated period of time has passed since the current image was presented or (b) when the user operates a "next image" control.
In some presentation programs, the visual transition from a current image to the image that follows it in the designated sequence (or "next image") is arbitrary. For example, often each row of pixels of the current image is replaced with the corresponding row of pixels of the next image, from top to bottom, as quickly as possible. Other presentation programs utilize a more sophisticated approach, according to which the user may designate that transitions between adjacent images are to be performed using special "transition effects". A transition effect is a graphical technique for visually depicting the transition from a source image to a target image. Transition effects generally involve either: (1) replacing portions of the current image with the corresponding portions of the next image according to some pattern, e.g., a checkerboard pattern; (2) progressively shitting one of the two images relative to the other, e.g., shifting the current image progressively to the right to reveal the next image "underneath"; or (3) manipulating brightness values in the palette used to display the images, e.g., making the current image appear to recede into darkness, then making the next image appear to emerge from darkness.
Some presentation programs allow the user to view demonstrations of different transition effects when the user is selecting a transition effect for a particular pair of images. Such demonstrations are performed using a "sample" current image and a "sample" next image. While such demonstrations may help the user to appreciate the general nature of different transition effects, the use of standard sample images makes it difficult to determine how the transition effect will look when applied to a particular pair of the actual images used in a presentation.
Typically, the user cannot assess the effect of assigning a particular transition effect to a particular pair of images used in a presentation without using the presentation mode of the presentation program to view the entire presentation at full size. This can be inconvenient, especially in cases where the user is experimenting with different transition effects for a particular pair of images.